Question

What will be the plain text corresponding to cipher text “EETPEG” if gronsfeld cipher is used with key “4321”?

(a) ABACUS

(b) ABROAD

(c) ABRUPT

(d) ABUSED

The question was posed to me in a job interview.

I'd like to ask this question from Cryptography topic in chapter Cryptography of Data Structures & Algorithms II

Answer 1

The correct choice is (b) ABROAD

Best explanation: Encryption in gronsfeld cipher takes place by shifting the letters of the plain text by a number given by the numeric key. So by applying the reverse of this method, we get the deciphered text to be “ABROAD”.